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LVIII. On Sharks. By William TathaMj i!,sqi 



SIR, 7b Mr. Tilloch. 



V/BSERVING in a shop window a print representing an ac- 

 cident which happened from the voracity of a shark in the 

 Ijarbour of Havannah, in the island of Cuba; and having 

 frequently noticed the propensity of the vulgar to swallow 

 extraordinary instances as matters of general existence (be- 

 lieving all the western hemisphere to be overrun with mon- 

 sters and savages, because geographers have, in some in- 

 stances, thought fit to ornament their productions with 

 Indians, bears, and snakes, with hideous creatures and 

 wild ferocity) ; it may not be unpleasant to communicate 

 to you a fact or two, within my own knowledge, touching 

 the scene of action in this print, which may not happen, to 

 be readily obtained from any other quarter. 



In the year 1793 I was on board the Philadelphia ship 

 Carolina, which was several weeks at anchor in the very 

 spot which this print exhibits; and I have been at the bot- 

 tom in the place where this accident happened : it is com- 

 posed of a blue or greenish clay, indented with small holes 

 as if made with the fingers, which I am inclined to think. 

 is the work of sn>all fishes, wherewith the harbour abounds; 

 and the clay is covered with a thin film, or skin, not unlike 

 brown paper. The w ater (probably from the shade of the 

 Savannas adjoining) has a greenish appearance, and is re- 

 plete with a small species of worm, or maggot, similar to the 

 skippers in rotten cheese. I understood, however, that it is 

 rtot this but another species of worm which renders it ne- 

 cessary to copper the bottoms of the ships j nor do the Spa- 

 niards ascribe to them any species of depredation, although 

 the surface of the harbour at some times exhibits them as 

 a kind of cream on the bason's contents.;. This subject may 

 nevertheless merit the investigation of ship owners; and 

 it may also deserve consideration how far chemical know- 

 ledge may be directed to the discovery of some cheap sub- 

 stitute for copper, which may be rrlorc generally applied to 

 ships in the merchant service, thereby economizing the con- 

 sumption of a material which constitutes the basis of a con- 

 siderable portion of British nianuiacture and commerce. 



I beg leave to state, in regard to the case of th.e shark, 

 that it is by no means my intention to encourage further 

 experiments at the bottom of the harbour of the Havannah : 

 6n the contrary, I observed the Spaniards frequently bathing 

 near the tJ;urfcs, lui never in the deep water, where the crev/ 



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